nahco3 metabolic acidosis

1. NaHCO3 in Acidosis
Abdalmohsen Ababtain

2. Objectives
• What’s Bicarbonate
• How it works
• Dose ?
• How can we give it
• Contraindications and Safety
• Who do you want to give it?
• When shall we use it
• Bicarbonate Disadvantages
• Bicarbonate Alternatives

3. What’s Sodium Bicarbonate

4. What’s Sodium Biacarbonate ?
• IV fluid with pH of 8.0
• 8.4% solution contains 1 mEq/mL of NaHCO3
and is very hypertonic (2,000mOsm/kg)
• 7.5% solution contains 0.9 mEq/mL of NaHCO3
• 4.2% solution contains 0.5 mEq/mL of NaHCO3

5. How It works

6. • Bicarbonate binds to H then breaks down into
CO2 and water in the blood.

7. • One Ampule of bicarbonate fully reacted will
generate over 11 of CO2 and 1.5 meq/L of Hco3
• Resp Acidosis, So what ?
Current Opinion in Critical Care 2008, 14:379–383

8. • Respiratory Acidosis Decreases left ventricular
contractility but increased overall CO by 23%
due to decrease SVR and increase HR
Circultion Research 1990;67:628-635

10. Dose ?

11. Dose
• Based on the calculated Deficit :
• HCO3
-(mEq) = 0.5 x weight (kg) x [24 - serum
HCO3
-(mEq/L)]
• Administer 1/2 dose over 3-4 hrs, then
remaining 1/2 dose over the next 24 hours;

12. • If acid-base status is not available: 2-5 mEq/kg
I.V. infusion over 4-8 hours; subsequent doses
should be based on patient's acid-base status
• initial goal of therapy is to target a pH of ~7.2
and a HCO3
- of ~10 mEq/L to prevent
overalkalinization.

13. How can we give it ?

14. • 100 meq of NaHco3 in 400 mL sterile water
at rate 200ml/hr
• 150 meq of NaHco3 in 1 liter or D5% or ½ NS
at rate 150-200cc/hr

15. Bolus !!

16. No Hco3 Bolus
• IV-push administration should be reserved for
cardiac life support whenever indicated and not
metabolic acidosis
Koda-Kimble M, Young LY, et al. Handbook of Applied Therapeutics. Lippincott Williams & Wilkins, 2006. P10.3(1104)

17. Is Sodium Bicarbonate Safe ?

18. Safety
• Pregnancy Risk Factor C
• Breast-Feeding Considerations Sodium is
found in breast milk
• Still No Enough Data !!
•Do you Really Care ?

20. Extravasation management
• Stop infusion immediately and disconnect (leave
cannula in place); gently aspirate extravasated
solution (do NOT flush the line); initiate
hyaluronidase antidote; remove cannula;
apply dry cold compresses elevate extremity.
• Hyaluronidase: SubQ: Inject four to five
separate 0.2 mL injections of 15 units/mL
around area of extravasation (Hurst, 2004).
Dimens Crit Care Nurs. 2004 May-Jun;23(3):125-8

21. Potential harms of bicarbonate
therapy
• Increased PCO2
• Hypernatremia
• Extracellular fluid (ECF) volume expansion
• Intracellular and CSF Acidosis (CO2)
• Hypokalemia
• severe tissue necrosis if extravasation takes
place
• rebound alkalosis
Ann Intern Med. 1986;105(6):836
Diabetes 1974, 23:405-411
N Engl J Med 1971, 284:283-290

22. • bicarbonate increases lactate production by:
• increasing the activity of the rate limiting
enzyme phosphofructokinase and removal of
acidotic inhibition of glycolysis
• shifts Hb-O2 dissociation curve, increased
oxygen affinity of haemoglobin and thereby
decreases oxygen delivery to tissues
• hyperosmolality (cause arterial vasodilation and
hypotension)

23. • Reduced ionized calcium by 10% (10% drop may
decrease cardiac and vascular contractility and
responsiveness to catecholamines)
Ann Intern Med. 1990;112(7):492-498

24. Before you Give Bicarb :
• Correct the underlying cause of acidosis and give
supportive care
• Ensure adequate ventilation to eliminate CO2
• Correct hypoxia
• Think twice before you give it in high anion gap
acidosis

25. Contraindications
• Alkalosis
• Hypernatremia
• severe pulmonary edema
• hypocalcemia

26. Why do you want to give bicarb ?
• What are the deleterious effects of acidemia, and
when are they manifest?
• When is acidemia severe enough to warrant
therapy?

27. Why do you want to give bicarb ?
• metabolic acidosis leads to adverse
cardiovascular effects:
• Reduced left ventricular contractility
• Arrhythmias
• Arterial vasodilation and venoconstriction
• Impaired responsiveness to catecholamine
vasopressors

28. What Are we Treating ?

29. Bicarbonate in DKA
Is it beneficial !

30. Does bicarbonate improve
management of severe DKA ?
• Ann Pharmacother. 2013 Jul-Aug;47(7-8):970-
5:
• Intravenous bicarbonate therapy did not
decrease time to resolution of acidosis or
time to hospital discharge for patients with
DKA with an initial pH <7.0.

31. • Crit Care Med. 1999 Dec;27(12):2690-3:
• Not in favor of the use of bicarbonate in the
treatment of diabetic ketoacidosis with pH
values between 6.90 and 7.10.

32. • Ann Intern Med 1986;105:836–840:
• administration of bicarbonateto pt with pH
(6.9 to 7.14) does not affect recovery outcome
variables as compared with those in a control
group.

33. In Pediatrics
• Ann Emerg Med. 1998. Jan;31 (1):41-8.:
• Prolonged hospitalizations were noted in the
bicarbonate group
• No evidence that adjunctive bicarbonate
improved clinical outcome in children with
severe DKA (pH < 7.15).
• The rate of metabolic recovery and
complications were similar in patients
treated with and without bicarbonate

34. Systematic review of 44 studies :
• Ann Intensive Care. 2011 Jul 6;1(1):23
• Showed increased risk for cerebral edema and
prolonged hospitalization in children who
received bicarbonate, and weak evidence of
transient paradoxical worsening of ketosis, and
increased need for potassium supplementation

35. Bicarb Increases Ketosis :
• Br Med J (Clin Res Ed). 1984 October 20; 289(6451):
1035–1038.
slower rate of lactate clearance, implying
impaired tissue oxygenation
• J Clin Endocrinol Metab. 1996 Jan;81(1):314-20
The group receiving NaHCO3 showed a 6-h
delay in the improvement of ketosis as
compared with controls

36. Cerebral Edema in Pediatrics
• N Engl J Med 2001;344:264–269
• cerebral edema occurs in approximately 1%
of episodes of DKA in children with a
mortality rate of 40-90%
• only treatment with bicarbonate was
associated with cerebral edema

37. Cerebral Edema Risk Factors
• Use of bicarbonate
• Younger age
• newly diagnosed diabetes
• hypocapnia
• Severe acidosis
• higher serum glucose, urea nitrogen, and
creatinine concentrations at the time of
presentation
N Engl J Med. 2001;344(4):264
J Pediatr. 1980;96(6):968

38. Conclusion
• Do not use NaHCO3 routinely in the
management of DKA
• Despite the lack of evidence many intensivists
have a personal cut-off pH at which they
consider giving HCO3- in severe acidemia due to
DKA (typically < pH 6.9 to 7.0) as a ‘last ditch’
measure

39. Ann Intern Med. 1987;106(4):615
• To be used in collapsing pt.
1) patients with a pH <7.0, in whom decreased
cardiac contractility and vasodilatation may
be impairing tissue perfusion
2) patients with severe hyperkalemia
3) patients with coma

40. If you want to give it
• patients with a pH <6.9, 100 meq of Hco3 in
400 mL sterile water at a rate of 200 ml/h.
• pH of 6.9–7.0, 50 mmol sodium bicarbonate
is diluted in 200 ml sterile water and infused at
a rate of 200 ml/h.
• No bicarbonate is necessary if pH is >7.0
Diabetes Care January 2004 vol. 27 no. suppl 1 s94-s102

41. American Diabetic Association (ADA)
• Says bicarbonate “may be considered” in
patients with pH < 6.9 in DKA
• High level evidence is lacking !!

43. Lactic Acidosis
• the most common cause of metabolic acidosis in
hospitalized patients
• Type A :due to marked tissue hypoperfusion in
shock
• Type B : toxin-induced impairment of cellular
metabolism
• Metformin
• Alcoholism
• Malignancy
• HIV infection

44. D-lactic acidosis
• rare form of lactic acidosis that can occur in
patients with short bowel syndrome or other
forms of gastrointestinal malabsorption who
ingest large amount of carbohydrates
• Ingestion of propylene glycol
• Some DKA Patients

45. Lactic Acidosis
• Lactic Acidosis that is severe enough to warrants
Bicarb therapy already has a high mortality to
begin with
• Literature Review done :
• Chest. 2000 Jan;117(1):260-7
• we do not give or advise bicarbonate
infusion regardless of the pH.

46. Uptodate
• suggest that patients with lactic acidosis and
severe acidemia (pH <7.1 and Hco3 below or
equal to 6 meq/L ) receive bicarbonate therapy
(tube the pt. if PCo2 >20 for Inadequate
ventilation)

47. Review Article
• In view of the paucity of data, we are not able to
agree or disagree with Bicarb treatment
• we do not think that bicarbonate administration
is indicated for LA due to shock if pH > 7.0
Current Opinion in Critical Care 2008, 14:379–383

48. • in hemorrhegic lactic acidosis on animal study
Bicarbonate treatment along with
hyperventilation and calcium administration
increases pH and improves cardiovascular
function
Anesthesiology. 2013 Nov 20

49. Bicarb and Mortality
• Sodium bicarbonate administration was an
independent factor associated with higher
mortality
PLoS One. 2013 Jun 5;8(6):e65283

50. • Sodium bicarbonate elevated blood lactate
concentrations to a greater extent than did either
sodium chloride or no treatment.
Science 15 February 1985

51. prospective randomized, double-blind,
controlled clinical trial
• I: in first stage sodium bicarbonate was given by
venous drip until pH≥7.15, and in second stage
sodium bicarbonate was given by intravenous
drip till pH≥7.25 after 6 hours
• C: intravenous drip of sodium bicarbonate was
used till pH≥7.15
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2013 Jan;25(1):24-7

52. Their conclusion !!
• The use of sodium bicarbonate in stages in
treating hypoperfusion induced lactic acidemia
as a result of septic shock can lower the
occurrence rate of multiple organ dysfunction
syndrome, time of mechanical ventilation,
durations of stay in ICU and in hospital, and
mortality
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2013 Jan;25(1):24-7

53. Surviving Sepsis Campaign 2012
• We recommend against the use of sodium
bicarbonate therapy for the purpose of
improving hemodynamics or reducing
vasopressor requirements in patients with
hypoperfusion-induced lactic acidemia with pH
≥ 7.15 (grade 2B).
• No good Evidence on pH< 7.15

54. PH>7.1
• Two randomized trials failed to find a benefit of
bicarbonate therapy in critically ill patients with
lactic acidosis and pH values > 7.1

55. Prospective, randomized, blinded,
crossover study
• Correction of acidemia using sodium
bicarbonate does not improve hemodynamics in
critically ill patients who have metabolic acidosis
and increased blood lactate
• pH (from 7.22 to 7.36) and serum bicarbonate
(from 12 to 18 mmol/L)
Ann Intern Med. 1990 Apr 1;112(7):492-8.

56. Prospective, randomized, blinded,
crossover study
• Bicarbonate therapy significantly increased the
arterial pH (from 7.16 to 7.21) and serum
bicarbonate (from 16 to 19 mmol/L)
• The infusion of sodium bicarbonate and sodium
chloride produced similar changes in cardiac
output, mean arterial pressure, and pulmonary
artery pressure
• Improving Numbers not M&M
Ann Intern Med. 1990 Apr 1;112(7):492-8.

57. Prospective, randomized, blinded,
crossover study
• Administration of sodium bicarbonate did not
improve hemodynamic variables in patients with
lactic acidosis, but did not worsen tissue
oxygenation.
Crit Care Med. 1991 Nov;19(11):1352-6

58. Case Report
• 43-year-old woman K/c HTN on atenolol and
Anxiety on Mirtazipine and lorazepam was
brought to the hospital with chest pain for 20
hours radiating to her Back
• Temp 32.5C BP 66/45 mmHg HR 57
• Denied Hx of Ingestion
• Tx as Septic Shock due to pneumonia
• 4 hrs later her condition deteriorated, Got tubed
Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

59. • pH 6.56, bicarbonate 3 mmol/L, and lactate
18.4 mmol/L
• AG 31
• serum creatinine of 162 μmol/L with a serum
potassium of 5.3 mmol/L
• Hco3 Infusion Started
• NE, Dobutamine, phenylephrine and
Vassopressin Started
Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

60. • PAN CT and TEE was Done INCONCLUSIVE for
aortic disease
• A Nurse Calling you for K+ 7.8 and GC
1.2mmol/l
• AG 43
• Urine Tox Positive for Benzo and opioid
• Serum tox Acetaminophen level 81µmol/L
• Chart Arrived and shows a suicidal attempt 15
years ago by overdose
Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

61. • A member of the family revealed that she have
DM and on metformin
• Metformin Level 170µg/mL (therapeutic range
1-2µg/mL)
• CRRT Started
• THAM, 0.3 mmol/L, 36 mg/mL, 1600 mg
administered by infusion at 300 mL/hr for 5
hours
Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

62. 90 mg Metformin !!
• Afterward Pt improved, Extubated Admitted
Taking 90 mg Metformin
Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

63. Metformin Toxicity
• Dtsch Med Wochenschr. 2000 Mar
3;125(9):249-51
• Conventional management of the lactic acidosis
neither corrected the acidosis nor stabilized the
circulatory system. Continuous veno-venous
haemodialysis with bicarbonate-buffered
solutions succeeded in reducing the need for
catecholamines

64. Metformin Toxicity
• Diabetes Care June 1999 vol. 22 no. 6 925-927
• 9 per 100,000 person-years
• Biguanides and NIDDM.Diabetes Care 15:755–
772, 1992
• Metformin. N Engl J Med 334:574–579, 1996
• The lactic acidosis rate in metformin
users has been reported to be much lower: 0–
8.4 cases per 100,000 person-years

65. Risk factors
• age of >60 yr
• decreased cardiac
• Hepatic Disease
• renal function
• diabetic ketoacidosis
• surgery
• respiratory failure
• ethanol intoxication
• fasting

66. Severe acidosis in Trauma
• retrospective therapeutic cohort study of 225
severely acidotic (arterial pH ≤ 7.10) between
1989-2011
• if dead space in the lungs increases due to shock
with poor lung perfusion, the arterial-end tidal
PCO2 difference [P(a-ET)CO2] increases
J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

67. • 2-8 vials of HCO3 given
• HCO3 10.5 (3.1) to 16.8 (4.0) mEq/L
• PaCO2 44 (9) to 51 (11) mmHg
• end-tidal CO2 stayed relatively constant 26 [6] to
25 [5]
• P(a-ET)CO2 from 17 (9) to 24 (13) mmHg
• More Dead Space !
J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

68. • 75 patients who survived had P(a-ET)CO2 10 (6)
mm Hg
• 103 patients who died in the operating room or
within 48 hours of surgery had a P(a-ET)CO2 of
23 (10) mm Hg
J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

69. • We have found that in severely injured patients,
P(a-ET)CO2 of less than 10 mm Hg is associated
with survival and P(a-ET)CO2 of greater than 16
mm Hg is usually fatal.
• Our initial studies suggested that intravenously
administered bicarbonate increases P(a-ET)CO2
J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

70. Sodium bicarbonate supplements for
treating acute kidney injury
• Cochrane Review was Done 2012
• We did not find any randomized controlled trials
(RCTs) that assessed the benefits or harms of
giving sodium bicarbonate to people with acute
kidney problems.

71. Bicarb is not that good !
• Tromethamine (THAM)
• Carbicarb
• Dichloroacetate (DCA)
• CRRT

72. Carbicarb
• is a mixture of Na2CO3/NaHCO3 that buffers
similarly to NaHCO3, but without net generation
of CO2
• Same risks of hypertonicity and hypervolemia
are similar to those of sodium bicarbonate

73. Comparing carbicarb Vs.bicarb in
hypoxic LA
• 28 Dogs with HLA Given 2.5 meq/kg of either
NaHCO3 or carbicarb over 1 hr.
• Lactate use by muscle, gut, and liver all
improved with carbicarb and decreased with
NaHCO3.
Circulation 77, No. 1, 227-233, 1988
Carbicarb Bicarb
PH (7.22 to 7.27 7.18 to 7.13
PCo2 No Change
Lactate Stabilized

74. • Twenty-one dogs were anesthetized,
mechanically ventilated, and randomly allocated
into:
• Carbicarb
• sodium bicarbonate
• sodium chloride
• Carbicarb administration in HLA improved
hemodynamics compared with sodium
bicarbonate or sodium chloride administration
Chest. 1993;104(3):913-918

75. THAM
• A biologically inert amino alcohol of low toxicity,
which buffers H+ and gets excreted in the urine
without production of Co2
• Administration of THAM in ALI cases was
associated with significant improvements in
arterial pH and base deficit, and a decrease in
arterial carbon dioxide tension
• Toxicities of THAM include hyperkalemia,
hypoglycemia, and respiratory depression
Am J Respir Crit Care Med. 2000 Apr;161(4 Pt 1):1149-53

76. Bicarb + THAM
• Using a blood-perfused isolated heart
preparation, left ventricular contractility and
relaxation were measured
• The combination of THAM with NaHco3 is
based on the ability of THAM to capture the CO2
produced by the sodium bicarbonate buffer. This
combination achieves a perfect correction of
metabolic acidosis and improves myocardial
performance.
Am J Respir Crit Care Med. 1997 Mar;155(3):957-63

77. CRRT
• Use bicarbonate-based replacement fluid over
citrate as citrate may increase the strong ion gap
Current Opinion in Critical Care 2008, 14:379–383

78. When shall we use it
• Accepted
• Hyperkalaemia
• Treatment of sodium channel blocker
overdose (e.g. tricyclic overdose)
• Urinary alkalinisation (salicylate poisoning)
• Metabolic acidosis (NAGMA) due to HCO3
loss (RTA, fistula losses)

79. • Controversial
• Diabetic ketoacidosis (very rarely, perhaps if
shocked and pH < 6.8)
• Severe pulmonary hypertension with RVF to
optimize RV function
• Severe ischemic heart disease where lactic
acidosis is thought to be an arrhythmogenic
risk

80. Cardiac Arrest
• The empirical early administration of sodium
bicarbonate (1 mEq/kg) has no effect on the
overall outcome in prehospital cardiac arrest.
However, a trend toward improvement in
prolonged (>15 minutes) arrest outcome was
noted.
• 2-fold increase in survival (32.8% vs 15.4%) !
Sodium bicarbonate improves outcome in prolonged prehospital cardiac arrest Am J Emerg Med. 2006;24(2):156

81. • retrospective cohort
• The administration of sodium bicarbonate at
around 36 Minutes of CPR did not significantly
improve the rate of ROSC in out-of-hospital
cardiac arrest
American Journal of Emergency Medicine 31 (2013) 562–565

82. No Benifit
• Buffer therapy during out-of-hospital
cardiopulmonary resuscitation. Resuscitation. 1995;29:89
–95. (RCT)
• Sodium bicarbonate improves outcome in pro-
longed prehospital cardiac arrest. Am J Emerg Med.
2006;24:156 –161.
• Prehospital bicarbonate use in cardiac arrest: a
3-year experience. Am J Emerg Med. 1992;10:4 –7.

83. • Out-of-hospital buffer therapy in heart arrest
Tidsskrift for den Norske Laegeforening : Tidsskrift for Praktisk Medicin,
ny Raekke [1996, 116(27):3212-3214

84. CRITICAL CARE
CLINICS VOLUME 14
NUMBER 3 - JULY 1998

85. ACLS Guidelines 2010
• Giving sodium bicarbonate during CPR is not
helpful and may even be harmful!
• (Class III, LOE B).

86. • Bicarbonate may compromise CPR by reducing SVR
• It can create extracellular alkalosis that will shift the
oxyhemoglobin saturation curve and inhibit oxygen
release.
• It can produce hypernatremia and therefore
hypersmolarity.
• It produces excess CO2, which freely diffuses into
myocardial and cerebral cells and may paradoxically
contribute to intracellular acidosis.
• It can exacerbate central venuous acidosis and may
inactivate simultaneously administered
catecholamines.

87. • prospective, randomized, double-blind,
controlled trial
• 36% receiving buffer were admitted to hospital
ICU and (10%) were discharged from hospital
alive, vs. (36%) and (14%) receiving saline
Buffer therapy during out-of-hospital cardiopulmonary resuscitation Resuscitation. 1995;29(2):89

88. Hyperkalemia
• Though no studies demonstrate harm, the solo
administration of bicarbonate does not acutely
decrease potassium levels. But it may improve
insulin/albuterol action on potassium in acidotic
patients.
• Don’t Give It Alone
• If you want to Give it Give as infusion (150mEq
in 1 liter D5%)
Miner Electrolyte Metab. 1991;17(5):297 Kidney Int. 1992;41(2):369

89. Rhabdomyolisis
• There is no evidence that bicarbonate is helpful
or harmful in rhabdomyolysis
• An excellent EBMedicine.net
review recommends bicarbonate if urine pH
<6.5 with CK level > 5000 as class III evidence –
indicating “it may be acceptable, possibly useful,
considered optional or an alternative treatment

90. bicarbonate is still recommended in
• TCA overdose
• Salicylate toxicity
• Phenobarbarbital
• Chlorpropamide
• Chlorophenoxy herbicide poisoning
• Cocaine overdose
• Organophosphate poisoning
• Methanol and ethylene glycol
• Increased ICP

91. Home Message
• Bicarbonate has many complication you have to
be aware of
• In NAGMA (Absolute bicarb loss) give it with no
doubt aiming for Hco3 20
• There are other options to Hco3
• Its usually a last resort choice after treating the
underlying disease

92. References
• Pubmed
• Uptodate
• Emcrit.org
• lifeinthefastlane.com